Electrical heater.



G. A. & L. EDMISON.

ELECTRICAL HEATER.

APPLICATION FILED MAY 26, 1913.

1 088 887 Patented Mar. 3, 1914. 2 SHEETS-SHEET 1. I53. I

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G. A. & L. BDMISON.

ELECTRICAL HEATER.

APPLICATION FILED MAY 26, 1913.

1,088,887. Patented Mar. 3', 1914.

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UNITED STATES PATENT ornios.

GEORGE A. EDMISON AND LAURENCE E-DMISON, OF LOS ANGELES, CALIFORNIA.

ELECTRICAL HEATER.

To all whom it may concern Be it known that we, Gnonen A. EDMISON and LAURENCE EDMIsoN, both citizens of the United States, residing at Los Angeles, county of Los Angeles, and State of Cali fornia, have invented a new and useful Electrical Heater, of which the following is a specification.

This invention relates to a novel combination of parts whereby the heating action in electrical stoves and other electrical heating appliances may be efiiciently and conveniently carried out.

Among other features of novelty the invention is characterized by a new arrangement of the heating coil itself. This consists primarily of a hollow vertical iron tube having resistance wire wound thereon. hen electricity is passed through the wire the same is electrically heated and some 01 its heat passes into the surrounding air. Another portion of its heat, however, passes into the spool on which it is wound, and. if this was solid a relatively great quantity of heat would be uselessly stored therein. Also while starting the apparatus the heat stored in a solid spool would diminish the coils heating effect so far as the exterior air was concerned, so that the heaters efliciency would be low until the full quantity of heat was stored in the spool. In this invention, however, the spool is made in the form of a hollow vertical tube which is open above and below, so that air may pass up and through the tube and abstract the heat therefrom. In this manner the walls of the tube may be made thin so that the quantity of heat stored therein is practically negligible. Also since the tube is vertical, air tends to pass up therethrough and to diminish the heat storing capacity of the tube. The tube is preferably made of iron so that when alternating current is used the magnetic effect thereof will warm the tube, and thereby increase the heating capacity.

The foregoing construction may be used separately for several purposes, but when used in an electrical stove a second outer tube, which is open above and below, is mounted so as to embrace the tube mentioned above. In this event a very effective heating action may be secured and the heating wire is inclosed so as to avoid the danger of persons coming in contact with same. A series of such heating units may be used to form a single stove, and other novel features Specification of Letters Patent.

Application filed May 26, 1918.

Patented Mar. 3, 1914.

Serial No. 770,061.

hereinafter described may be combined with these units so as to form a safe, gainly and salable stove.

The following figures illustrate the invention.

Figure 1 is a plan View of an electrical stove embracing this invention. Certain parts have been broken away so as to display other parts. Fig. 2 is a front elevation of the same stove partly in section. Certain parts have been broken away to display other parts. Fig. 8 is an end elevation of the same stove partly in section. Certain parts have been broken away so as to display other parts. Fig. 4 is a vertical section of the stove, the section being on line w mfl Figs. 1 and 2. Fig. 5 is a fragmental section on line m:0 Figs. 1 and 4. Fig. 6 is a wiring diagram shown somewhat conventionally. This diagram illustrates the electrical connections when a series of heating coils are used.

In the figures a stove having three heating units a, Z) and c is shown, but it will be understood, of course, that any other convenient number of units may be used. The details of these units are substantially similar, and the construction shown in Fig. 5 may be taken as being typical of any of the units. This figure shows a hollow vertical iron tube 2 having a layer of mica or other insulating material 3 and a coil of electrical resistance wire 4. Around this is placed another vertical tube 5, preferably comprising two sepa rate tubes 6 and 7 separated by a layer of asbestos 8. Both of these tubes are open above and below so that air may circulate freely therethrough when the coil 1 is heated.

For the purpose of supporting the inner tube and of permitting suitable electrical connections between the coils on the several heating units, the ends of said inner tube are provided with annular porcelain caps 9. Across these caps suitable metallic strips 10 are fastened, and these metallic strips are electrically connected to the ends of coil f at 1.1 and 12, respectively. Across the portions 13 and 14 of said strips are bound the copper bars 15 and 16. The lower of these,i. 6., bars 16-are connected as shown in Fig. 1 to porcelain blocks 17 and 18, which in turn are rigidly fastened on base plate 19. The weight of the inner tube, therefore, rests upon the bars 16. On the other hand, the upper bar 15 is connected,

as shown in Fig. 4, to the porcelain bars 20 and 21, which are rigidly mounted along the top member 22. The outer tubes 5 are connected between the top and bottom members 22 and 19 respectively, and in any suitable manner, so that the top member 22 may be supported by said tubes, while said tubes themselves are supported by said bottom members.

Attention is now directed to the electrical connections whereby current is led into the heating coils. At one end the leads 23 and 24:, Fig. 6, are connected to an electrical power source 25, which preferably supplies alternating current. These leads pass into the stove through bushing 26 at one end of the bottom member 19see Figs. 2 and The lead 24 is then connected to the bottom copper bar 16 for the heating unit a. From this bar the current passes into the corresponding strip 14;, and from thence through connection 12 to the resistance coil 4. From this resistance coil the current passes out of unit a. through connection 11 to strip 13, and through the top bar 15 on heating unit a. Above the porcelain 20, Fig. 1, a copper bar 27 electrically connects cross bar 15 of unit a to cross bar 15 of unit bsee Fig. 6. The current, therefore, passes from unit (a to unit Z) through bar 27, and then passes downward through unit 6 similarly to the manner in which the same current flowed upward through unit (4. Another copper bar 28, Figs. 1, 1 and 6, is mounted below porcelain 18 on the base member 19, and electrically connects bottom bars 16 of units 6 and 0. The electrical current is therefore conducted from unit 6 to unit 0 through bar 28, and the current then passes up through unit 0 in a. man ner similar to that described for unit a. From the top bar 15 of unit 0 the current passes into lead 29 which is connected to one end of an operating switch 30. The other end of this operating switch is connected to the lead 23, and when the switch is thrown the electrical circuit is closed from the power source 25 through the several heating units a, b and c in the manner just described.

The lamp 31 may be connected into the circuit across the leads 24 and 29 as shown in Fig. 6. In the actual construction this lamp may be mounted in an appropriate casing 32 having an arched front 33, Figs. 1, 2, 3 and 4c. The sides of the arched front of this casing may be lined with isinglass 36, and by coloring either the isinglass or the lamp with a soft red or orange tint, the glow of the lamp would suggest something of the glow which makes the luminous open hearth fire popular. According to the connection in Fig. 6 it is seen that when switch 30 is thrown on, the heating units a, l) and c and the lamp 31 are simultaneously set into operation. In case the supply of electrical power at source 25 should fail, this fact would immediately be noted by the failure of light at lamp 31 in cases where the stove had been operating, or if the stove is just being started by the failure of lamp 31 to light up.

Attention is now directed to the manner in which the external air may enter the stove and may pass up through the inner tubes, and through the spaces between the inner and outer tubes of the heating units a, 5 and c, and to the manner in which the air may then escape back into the atmosphere through the upper member This circulation permits the air of the room to enter the stove, to be heated therein and to then pass out, and to spread its warmth into the room. For this purpose some suitable apertures 37 are provided in the base member 19 see Figs. 2 and 1. These apertures are shown in the form of circular holes, but any scroll or other well-shaped apertures may be used for ornamental purposes. The top plate 38 of the top member 22 is also provided with apertures 39 having a. circular or other preferred shape. The area of these latter apertures is practically made adjustable by having a second plate 4-0, Figs. 1, 2 and 3, slidably mounted beneath the top plate 38. The plate 10 also has apertures 39 spaced similar to and adapted to register with the apertures 39 in the top plate. A shifting handle 4-1, Fig. 2, is attached to the plate 40. lVhen this handle is moved back and forth the plate 40 slides through the guides l2see Fig. 4-,and the apertures 39 and 39 adjust themselves so as to change the area of the opening from one into the other.

hen electrical current is passing through the heating units air will be drawn into the stove through apertures 37, and this air may pass directly up between the outer and inner tubes of the heating units or may flow around the bottom strips 141:, and into and through the inner tube. The portions of air passing through the heating units by either of these channels will abstract the heat from the resistance wire and from the tubes. This heated air then passes freely into the upper member, and later passes out from the same through the adjustable apertures in the top plate. Heat, however, is also radiated and conducted from the resistance wire to and through the outer casing 5 of the heating units. In this manner the stove throws heat out sidewise from the heating units as well as upward from the top plate.

A plate 43, Fig. 4, may be mounted so as to span across the bottom member below the tubes of the heating units. This plate would serve to catch any hot portions of the heating wire which might break loose from the heating coil if the same became accidentally broken during operation.

From the foregoing detailed description the construction and operation of the stove embracing this invention is thought to be clear.

We claim 1. In an electrical heater, the combination of an outer hollow vertical tube open above and below, an inner hollow vertical tube, the second said tube being within and spaced apart from the first said tube to form an air passage, electrical resistance wire on the second said tube, electrical connections for connecting said wire to an electrical circuit so that said wire may be electrically heated, said heat being dissipated by conduction and radiation to and through said outer tube and by the upward. flow of the air between said tubes, said inner tube being also open above and below so that air may rise therethrough and abstract the heat therefrom.

. 2. In a portable electrical stove the combination of a lower base member, a top memher, an outer vertical tube connecting said base member with said top member, an inner vertical tube, said inner vertical tube being located within and spaced apart from the first said tube to form an air passage, electrical resistance wire on said inner tube, electrical connections for connecting said wire with an electrical circuit so that said wire may be electrically heated, said outer and inner tubes both being open below to said base member and both being open above to said top member, said base member itself being open to the atmosphere, and said top member also being open to the atmosphere and through adjustable apertures.

8. In a portable electrical stove the combination of a base member, a top member, a series of relatively large vertical tubes joining said base member with said top member, each of said large vertical tubes having a smaller vertical tube within, electrical resistance wire on each of said inner tubes, electrical connections for connecting said resistance wire to an electrical circuit so that said wire may be heated, said tubes being open below to said base member and being open above to said top member, a horizontal imperforate plate spanning across said bottom member below said tubes, said bottom member having apertures adapted to lead air from the atmosphere to and through said tubes, and said top member having adjustable apertures adapted to lead air from said tubes to the atmosphere.

4. An electrical heater comprising a base,

a top member, outer and inner tubes forming an air passage therebetween, a resistance unit around the inner tube, annular insulating caps at the ends of the inner tube, metallic strips fastened across said caps, 1ne tallic bars fastened to said strips, insulating blocks fastened to the base and supporting one of said bars, and other insulating blocks fastened to the top member and supporting the other of said bars.

In testimony whereof, we have hereunto set our hands at Los Angeles, California, this 17th day of May, 1913.

GEORGE A. EDMISON. LAURENCE EDMISON.

In presence of JAMES R. TOWNSEND, ROBERT A. STEP.

copiel of thil patent may be obtained for five cents each, by addressing the Commissioner of Paton". Washington, D. C. 

